/*
  main.c - An embedded CNC Controller with rs274/ngc (g-code) support
  Part of Grbl
  
  Copyright (c) 2011-2015 Sungeun K. Jeon
  Copyright (c) 2009-2011 Simen Svale Skogsrud
  
  Grbl is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  Grbl is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with Grbl.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "grbl.h"

// Declare system global variable structure
system_t sys;

int main(void) {
    // Initialize system upon power-up.
    serial_init(); // Setup serial baud rate and interrupts
    settings_init(); // Load Grbl settings from EEPROM
    stepper_init(); // Configure stepper pins and interrupt timers
    system_init(); // Configure pinout pins and pin-change interrupt

    memset(&sys, 0, sizeof (system_t)); // Clear all system variables
    sys.abort = true; // Set abort to complete initialization
    sei(); // Enable interrupts

    // Check for power-up and set system alarm if homing is enabled to force homing cycle
    // by setting Grbl's alarm state. Alarm locks out all g-code commands, including the
    // startup scripts, but allows access to settings and internal commands. Only a homing
    // cycle '$H' or kill alarm locks '$X' will disable the alarm.
    // NOTE: The startup script will run after successful completion of the homing cycle, but
    // not after disabling the alarm locks. Prevents motion startup blocks from crashing into
    // things uncontrollably. Very bad.
#ifdef HOMING_INIT_LOCK
    if (bit_istrue(settings.flags, BITFLAG_HOMING_ENABLE)) {
        sys.state = STATE_ALARM;
    }
#endif

    // Force Grbl into an ALARM state upon a power-cycle or hard reset.
#ifdef FORCE_INITIALIZATION_ALARM
    sys.state = STATE_ALARM;
#endif

    // Grbl initialization loop upon power-up or a system abort. For the latter, all processes
    // will return to this loop to be cleanly re-initialized.
    for (;;) {

        // TODO: Separate configure task that require interrupts to be disabled, especially upon
        // a system abort and ensuring any active interrupts are cleanly reset.

        // Reset Grbl primary systems.
        serial_reset_read_buffer(); // Clear serial read buffer
        gc_init(); // Set g-code parser to default state
        spindle_init();
        coolant_init();
        limits_init();
        probe_init();
        plan_reset(); // Clear block buffer and planner variables
        st_reset(); // Clear stepper subsystem variables.

        // Sync cleared gcode and planner positions to current system position.
        plan_sync_position();
        gc_sync_position();

        // Reset system variables.
        sys.abort = false;
        sys_rt_exec_state = 0;
        sys_rt_exec_alarm = 0;
        sys.suspend = false;
        sys.soft_limit = false;

        // Start Grbl main loop. Processes program inputs and executes them.
        protocol_main_loop();

    }
    return 0; /* Never reached */
}
